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The amount and spatial and temporal dynamics of vegtional LAI–SVI approaches to circumvent these limitaetation are important information in environmental studtions. The proposed strategy was implemented in three ies and agricultural practices. There has been a great sequential steps. In the first step, a BRDF model was indeal of interest in estimating(More)
Sixty-six patients with Duke's B2 or C colon or rectal cancer were randomized for treatment with aspirin (ASA), 600 mg, p.o., twice daily x 2 years or placebo (P). Compliance was checked in both groups by random measurement of blood salicylate levels. Fifty-seven patients are currently evaluable. No difference in disease-free (p = .66) or overall survival(More)
The Penman-Monteith equation is useful for computing evaporation rates of uniform surfaces, such as dense vegetation or bare soil. This equation becomes less useful for evaluation of evaporation rates at the regional scale, where surfaces are generally characterized by a patchy combination of vegetation and soil. This is particularly true in the arid and(More)
Surface roughness has a significant effect on the relationship between radar hackscattcr and soil moisture. In order to use cxistinR radar satellite data for soil moisture, roughness effects must be corrected. A technique is presented that utilises Ihe data bases from soil erosion sludies and soil moisture remote sensing investigations to provide firsl(More)
Decision makers historically have indicated that inaccessibility of required geographic data and difficulties in synthesizing various recommendations are primary obstacles to spatial problem solving. Studies have shown that the quality of decisions (i.e., the ability to produce meaningful solutions) can be improved if these obstacles are lessened or removed(More)
*James C. Ascough II, Marvin J. Shaffer, Gregory S. McMaster, Gale H. Dunn, Lajpat R. Ahuja, and Mark A. Weltz, USDA-ARS-NPA, Great Plains Systems Research Unit, 301 S. Howes St., P.O. Box E, Fort Collins, CO 80522; Dana L. Hoag, Colorado State University, Department of Agricultural and Resource Economics, Fort Collins, CO 80523; *Corresponding Author:(More)
The point sample method has been a standard plotless method for measurement of ground cover on rangelands since it was introduced by Levy in 1927. The instrument most commonly used to do point sampling is the point frame. Since its introduction, the point frame has undergone numerous modifications to improve efficiency and ease of use. This article(More)
Vertical surface properties of the landscape were measured using a laser altimeter mounted in a small twin-engine aeroplane. The laser altimeter makes 4000 measurements per second with a vertical recording precision of 0.05 m for a single measurement. These airborne laser measurements were analysed to provide information on topography, vegetation canopy and(More)
In the arid western United States, wildlife water developments, or ‘‘guzzlers,’’ are important water sources for wildlife, and consist of impermeable roof structures designed to intercept precipitation and small tanks for storing water. Guzzlers are typically installed in remote midto high-elevation basins, where precipitation data are often scarce. In this(More)